Synchronized phasors are time-synchronized values that represent both a voltage/current magnitude and a phase angle of electricity. Synchrophasors can be measured by high-speed monitors called Phasor Measurement Units (PMUs) located at various points in a power system. In operation, phasor measurement data from PMUs can be collected and aggregated to derive synchrophasors by a power data concentrator (PDC) operatively coupled to the PMUs via a communications network (e.g., the Internet). The PDC can “align” phasor measurement data from the PMUs based on time stamps to derived synchrophasors. The derived synchrophasors can then be used for monitoring and controlling operations of the power system, such as for maintaining a stable voltage in the power system.